## Compose sample application ### React application with a NodeJS backend and a MySQL database Project structure: ``` . ├── backend │   ├── Dockerfile │   ... ├── db │   └── password.txt ├── docker-compose.yaml ├── frontend │   ├── ... │   └── Dockerfile └── README.md ``` [_docker-compose.yaml_](docker-compose.yaml) ``` services: backend: build: backend ... db: image: postgres ... frontend: build: frontend ports: - 80:9000 ... ``` The compose file defines an application with three services `frontend`, `backend` and `db`. When deploying the application, docker-compose maps port 80 of the frontend service container to port 9000 of the host as specified in the file. Make sure port 80 on the host is not already being in use. ## Deploy with docker-compose ``` $ docker-compose up -d Creating network "react-express-mysql_default" with the default driver Building backend Step 1/16 : FROM node:10 ---> aa6432763c11 ... Successfully tagged react-express-mysql_frontend:latest WARNING: Image for service frontend was built because it did not already exist. To rebuild this image you must use `docker-compose build` or `docker-compose up --build`. Creating react-express-mysql_db_1 ... done Creating react-express-mysql_backend_1 ... done Creating react-express-mysql_frontend_1 ... done ``` ## Expected result Listing containers must show two containers running and the port mapping as below: ``` $ docker ps CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES 5e3ecd0289c0 nginx-golang-postgres_proxy "nginx -g 'daemon of…" 48 seconds ago Up 48 seconds 0.0.0.0:80->80/tcp nginx-golang-postgres_proxy_1 ffa1410b1c8a nginx-golang-postgres_backend "/server" 49 seconds ago Up 48 seconds 8000/tcp nginx-golang-postgres_backend_1 e63be7db7cbc postgres "docker-entrypoint.s…" 49 seconds ago Up 49 seconds 5432/tcp nginx-golang-postgres_db_1 ``` After the application starts, navigate to `http://localhost:80` in your web browser to get a colorful message. ``` My New React App ``` The backend service container has the port 80 mapped to 8080 on the host. ``` $ curl localhost:8080 Hello Docker World ``` Stop and remove the containers ``` $ docker-compose down Stopping react-express-mysql_frontend_1 ... done Stopping react-express-mysql_backend_1 ... done Stopping react-express-mysql_db_1 ... done Removing react-express-mysql_frontend_1 ... done Removing react-express-mysql_backend_1 ... done Removing react-express-mysql_db_1 ... done Removing network react-express-mysql_default ```